A driving experiment: New mixture used on icy roads
November 20, 2008
INTERSTATE 80 ” Caltrans is trying out alternatives to normal road salt this winter in an effort to keep the interstate ice-free.
Along with regular rock salt and a newer gritty salt from Utah called “Ice Slicer,” Caltrans crews will be trying out a salt water brine this winter to see if it melts ice faster and reduces salt usage and cost.
“We’ve never done this before,” said Shelly Chernicki, spokeswoman for Caltrans. “We’ll be keeping records comparing success and costs. We’re always trying to improve winter operations, and hopefully this is an improvement.”
Bryan Carlson, Donner Pass area maintenance superintendent said brine will allow Caltrans to use less salt, melt ice at lower temperatures and melt ice more quickly.
“It’ll melt snow and ice down to 10 degrees ” rock salt quits at 23 to 25 degrees,” Carlson said.
Normal salt relies on traffic to crush it, grind it into the salt, and spread it around before it starts melting snow. Brine starts right away, he said.
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This means without rain to wash it away, the brine will stick around for four or five days, compared to old methods of salting or sanding every night, Carlson said.
He said to mix the brine, Caltrans will draw from their own well and shouldn’t affect other water supplies.
Chernicki said Caltrans has also been using Ice Slicer for a few years along the interstate.
Nevada County Transportation Commissioner and Truckee Town Council member Carolyn Wallace Dee said Ice Slicer is a deep-mined natural salt from Utah.
Carlson said Ice Slicer, which has already been used on the western slope, will also melt ice and snow at lower temperatures, and is more coarse.
For brine, three 1,200 gallon mounted tanks on trucks, and one 3,000 gallon tanker truck will spread the brine solution, Chernicki said, putting down between 30 and 80 gallons per lane-mile.
Ice Slicer will be used at a rate of 50 to 100 pounds per lane-mile, Carlson said.
For comparison, regular road salt is normally applied at a rate of 200 pounds per mile of lane, he said.
The hope with starting the two materials in the Donner Summit area is to save money on material, time, and labor.
“We’re trying to do our part with this state budget,” Carlson said.
He said on average Caltrans uses 5,900 tons of salt along the I-80 coridor, and at an average of $80 per ton, that comes to about $472,000.
Along with saving money, putting less salt on the road by using brine and Ice Slicer, environmental ramifications could be reduced as well, said Bryan Carlson, Donner Pass area maintenance superintendent. This will also be monitored over the winter as part of the pilot project.
Jason Rainey, executive director of the Nevada City-based South Yuba River Citizens League said they will also keep an eye on the salt in local streams.
“We added a new test site over a year ago on upper Castle Creek in the Donner Summit area, which has shown during deicing operations to have 20 to 30 times the salt as the baseline,” Rainey said.